[tex]1. \begin{array}{ccc}9\\56\end{array} - (\begin{array}{ccc}7\\15\end{array} - \begin{array}{ccc}5\\12\end{array}) (\begin{array}{ccc}3\\14\end{array} + \begin{array}{ccc}1\\2\end{array})=... 

2.(\begin{array}{ccc}2\\3\end{array} + \begin{array}{ccc}7\\8\end{array} - \begin{array}{ccc}5\\6\end{array}) (1 - \begin{array}{ccc}5\\17\end{array})=...[/tex]

спс

пжлст

9/56-97/15-5/12)*(3/14+1/2)=9/56-(28/60-25/60)*(3/14+7/14)==9/56-(1/2*5/7)=9/56-1/28=9/56-2/56=7/56=1/8(2/3+7/8-5/6)*(1-5/17)=(16/24+21/24-20/24)*(17/17-5/17)==17/24*12/17=1/2